I don't even get a login screen. Just a message saying that the connections was disconnected.
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CJ7Jun 8 '10 at 8:27

Understood. Then check: (1) Can you ping the machine? (2) Can you connect to the port? (i.e. is the port in the remote computer open to you? use utilities such as nmap (google nmap).) Here, (1) If you can connect to the port, but unable to connect --> protocol problem. - then check RDP version, client setting, server setting e.g. is there forced encryption? (2) If you can't even connect, check firewall(s) in between. some ISP blocks RDP.
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bubuJun 8 '10 at 15:37

What do you mean by "same level"? I can get Remote Assistance working so the firewalls are not blocking that port.
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CJ7Jun 7 '10 at 14:09

@Craig Johnston: I mean that the RDP software is same version, although that's a somewhat long shot. As a remark: it wouldn't hurt to reinstall the RDP client, even if same version. I also erased the unsuitable port suggestion.
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harrymcJun 7 '10 at 14:35

Make sure that Remote Desktop is enabled (it's a separate checkbox from Remote Assistance) and make sure that your version of windows includes Remote desktop - Home version does not, but Professional does.